#define  _CRT_SECURE_NO_WARNINGS
class Solution
{
public:
    string minWindow(string s, string t)
    {
        int hash1[128] = { 0 }; 
        int kinds = 0;
        for (auto ch : t)
            if (hash1[ch]++ == 0) kinds++;
        int hash2[128] = { 0 }; 
        int minlen = INT_MAX, begin = -1;
        for (int left = 0, right = 0, count = 0; right < s.size(); right++)
        {
            char in = s[right];
            if (++hash2[in] == hash1[in]) count++; 
                while (count == kinds) 
                {
                    if (right - left + 1 < minlen) 
                    {
                        minlen = right - left + 1;
                        begin = left;
                    }
                    char out = s[left++];
                    if (hash2[out]-- == hash1[out]) count--; 
                }
        }
        if (begin == -1) return "";
        else return s.substr(begin, minlen);
    }
};